Method of electrodeposition of metals and alloys



Sept. 30, `193.0. L. LlNlcK METHOD OF' ELECTRODEPOSITI'ON OF' METALS AND ALLOYS Filed Nov. 3, 1927 2o cious vand a base metal in composition Patented Sept. 30, 1930 f UNITED sin.

LESLIE LLOYD LINICK,

OF CHICAGO, ILLINOIS METHOD or ELEc'raoDEPosIrIoN or METALS Nn annoys Application med November 8, 19277. Serial No. 230,927.

This invention relates to a method of electro-deposition of metals and alloys, and among its objects are to producev a closer grained deposit than heretofore; to produce a faster deposit from a given solution. withl out burning the cathode; to produce an equal or superior deposit from a weaker solu- H tion or from a given solution with. a weaker current or lesser wattage; to produce Va deposit of greater cohesion to its base; to produce a good deposit from a solution from which, otherwise, no electro deposit could be obtained, or only to a limited extent, or only erratic results could be obtained; to produce a good deposit of two o r more metals in composition from solutions, which, otherwise, could not plate compositions or alloys; to4 obtain a deposit of precious metal directly upon aluminum; to obtain .a deposit of prerectly upon aluminum land directly upon precious metal; to deposit metal upon plated ware. Other objects and advantages will occur in the course of this specification and with all of 'said objects and advantages'in view, this invention consists in a method of electro-deposition of metals and alloys, with the use of an' anode, in tube form, or contained in a glass tube or atube made of other 3o non-conducting insoluble material, and carrying and emitting an active gas under pressuregto the surface or just below the surface of an electrolyte. It furtherconsists in the method of electro-deposition'of metals and sure, is introduced at orbelow the surface of an electrolyte for the' purpose' of electro Avplating. It. further consists inthe several novel features hereinafterfully set forth and particularly pointed out in the appended f claims. V v

A simple form of apparatus for carrying on the method forming the subject matter of this specification is illustrated in the' aecom- "panying drawing in which- Y g Figure 1 is a dic view of the apparatus, partly in side elevation and partly in vertical section; and: no VFig. 2 is an enlargeddetailvertical nore reservoirs or gas tanks alloys, wherein an activegas, under prestion0 through a certain anode supportingnioat employed 1n the apparatus.

Referring to said drawing, the reference character 3 designates a plating tank in which the electrolyte is contained. xOne or 4 are employed in which are' separatelyn contained active gases, such, as hydrogen or oxygen, under pressure. Associated with each tank 4 is a pressure regulatingvalve 5 which is interl osed in a main supplyjpipe 6 that leads rom the gas tank 4, and said valve furnishes means whereby the pressure of the gas deliveredfinto the solution in the plating tank may be regulated to obtain thedesired re- .65 sult. A gauge 7 communicates with the pressure tank and indicates the pressure therein.

Interposed in the -main supply pipe 6 beyond the pressure regulating valve 5 is-a. needle or other valve 8 for regulating the volume of gas delivered from the supply pipe.

-Adjacent said valve 8 is a, gauge A9 for show-- ing the,pressure of the gas which is being used. Leading from theinain supply pipe 6 ais a flexible tube or supply pipe 1() which s runs to a heade -1l supported above the plating tank, and from said header lead individual flexible tubes or supply pipes 12 that are controlled by valves 13 interpos d between the header and the individual exible tubes 12.. Thedischarge ends ofthe iiexible .tubes 12 are supported directly above the surface of the plating solutionin-the plating tank 3,' as, for instance, .by iioats 14 that rest upon the solution and are attached to theiexible tubes by bars `15 secured to the floats and having attaching' nipples 16 fastened thereto,- as best seemin Fig. 2. Theflexible tubes 12 are slipped upon the'en'ds of .the attaching- 9o nipples 16, andin the lower, ends' of said at-1 taching nipples are tubular anodes 17 preferably composed of platinum. The attaching nipples 16,'are preferably'l formed ofmetal, and from said metal nipples extend the' 95 positive wires 18 ofthe plating circuit. -AsA many floats, as supply tubes and l anodes Amay emp oyed .as is found bestV suited for the particular work at hand. As I a preference, the floats with the anodes sup-v 10o ported thereby are placed around lthe sides of the plating tank with the discharge oriice of the anodes touching the surface of the plating solution or barely immersed therein. A cathode 19, namely, the artlcle or t articles to be plated, is placed at or near the Chromic acid-, four ounces Pyrogallic acid; ...en eighteen grains Boric acid ten grains Chromium sulphate ten grains Sugar twenty-five grains The above ingredients should be dissolved in hot water in the order given.A WVhen hydrogen gas is employed, the pressure of the hydrogen introduced into the plating tank should be approximately six ounces and the volume thereof should be sufficient to envelop the submerger parts of the anodes, Ap roximately from five to six volts of E. F. should be used at about one-tenth to one-eighth amperes per sfuare inch of submerged cathode surface. he length of plating time should be from one minute to more, and the temperature of the plating solution should be about one-hundred-iifty to one-hundred-sixty degrees Fahrenheit.

A solution containing chromium and platinum, for instancechromic acid and platinum chloride has been used. to. a great advantage.'

The following is an example of said solution:

Water one-half gallon Chromic acid '-gfour ounces Y Platinum chloride l one-half ounce Ammonium oxalate one-half ounce Sodium phosphate one-halfounce Benzoic acid l thirty grains Saccharose twenty grains Aluminum sulphate twenty grains The above ingredients should be dissolved in hot water in the order given. The pressure of the hydrogen introducedg into; the bath should be approximately four ounces and thatof the oxygen should be approximately three ounces. The volume of the gases should be just sufficient to Vpractically surround the submerged portions of the anodes. Approximatelyfive volts of E. M. F. should be used at about one-fifteenth to one-tenth amperes per square inch of submerged cathode area.

the gas tank The length of-trne :for plating .should beapproximately two minutes or more, and

the temperature of the bath should beabout interrupted or pulsating effect on the elec-" tric current passing into the solution.

In the electrolyte formed by the solution, or just touching its surface, if desired, is placed a small anode or a number of small anodes, which may be of tubular or similar form, connected to a gas tank or other reservolr by a suitable conduit, which tank or such asoxygen or reservoir contains gas, hydrogen, under pressure, capable oi' being regulated by a suitable 'pressure regulating device and has control means, such as a needle valve, for regulating the flow or quantity of gas admitted to the solution.A The anode .or anodes are conn'ected to the positive Aterminal of the plating line. and the cathode is connected to the negative terminal ofthe plating line as is Well understood. i

Specifically, a platinum hollow wire or tube of relatively small diameter and length may be used as ananode and this may Abe soldered to a copper tube. The tube may be connected a flexible connection, such as a rubber hose, to the needle valve of a hydrogen or oxygen tank, provided with-the usual pressure regulation means. The copper turbe is lconnected bv-a copper wire to the positiveterminal of theplating line. The hydrogen or oxygen (depending upon which gas is used) is allowed to flow to and through the platinum tube at a loW pressure, for instance four ounces of pressure, with the platinum tube partly submerged in the solution or' placed with its lower end in contact with it. The articles to be plated being placed in the solution and connected with the negative side of the plating line, the needle valve o f is opened and the gas permitted to discharge into the solution or on the sur'- face thereof andthe electric current is turned on for the required l gth of time few seconds and upwagds) to obtain Athe desired thickness of plate. Instead of employin as the anode, the ano e within a small glass tube and connected to the positive terminal of the plating line, and the glass tube connected by a suitable conduit, to the gas tank or reservoir.

the platinum tube may be contained (from a In either event, Whether a single anode such as hydrogen A3() Q other methods of electro-plating to the surface of the solution,

, the escaping gas may completely envelop the P an active gas under regulated pressure are solution, which gas or gases envelop the anode v many times in excess of the natural gasing of an anode or electrode in an active plating solution.

When hydrogen and oxygen are both used they are brought'to the solution in separate conduits and not as a mixture. Owing to the highly inflammable nature of these combined gases, it is1 advisable to install a. suitablesuction blower to carry olf the escaping gases.

The anodes should be submergedalike and remain at a constant depth and' in order to hold them at a constant depth, I use floats, inthe center of each of which an anode is fastened, and I place the ioats on the solube made of hard wood Where any metal is used in the floats to support the anodes, such metal whether in the forni of spokes or arms, should be place above the surface of the solution. By supporting the anodes from the floats, the anodes are held in a vertical position, gles to the surface of the solution, whereby anodes. f Y

Comparing results of ny method with I have found, that bythe use of the hereinabove described process I am enabled to:

1. Obtain a closer grained deposit, thus simplifies or eliminates subsequent polishing. This is of particular advantage wit all plating, but especially in the plating of metals that are hard to polish, such as platinum, iridium, chromium, cobalt, tungsten, nickel and alloys of these metals.'

2. Produce a faster deposit, from a given solution, without burning the cathode, or

3. Produce an equal or superior deposit from a weaker solution, or

4. Produce an equal or superior deposit from a given solution with a weaker current i from which, otherwise,

` from which, otherwise,

are obtained.

, vall or a lesser wattage. Y 5. Produce a deposit. of greater cohesion Y to its bas'e.

6. Produce a good deposit from a solution from' which, otherwise, could be obtained.

7. Produce a good deposit'froml a solution electro-deposition limited extent..

could be obtained only to a om a, solution 8. Produce a good deposit 'only 9. Produce a goodfdepo'sit of two metals, in composition, from solutions, whic otherwise, could not plate compositions -or oys. 10. Obtain a deposit oprecious metal directly upon aluminum.

g ABy experiment, I 'haveA found thatthe dvother metals,

at right anwhich A P organic substances,

no electro-deposit P rratic results.

. ing continuously or more h the mechanical action of the gas or gases upon to the volume of the cathode, to the rateof the current used and to the displacement of the anode. Thus, with a bulky article, I use a greater anode surface, represented by more anode tubes in number, and a correspondingly greater pressure of the gases employed, which in turn regulates the iiow 'of current independent of rheostatregulation. By the use of several banodes, barely submerged and emitting hydrogen from one and oxygen from the other, proved 'in many cases'. gases and others, singly and together, with one or more anodes, soluble and otherwise vfor electro-deposition purposes'andhave 0b,-

tained the results mentioned in this speciication.

I find it advisable where hydrogen and oxygen are both employed to use an excess the deposition is greatly im- I have used these of hydrogen withprecious metals in general,

and with chromium and cobalt. With most I use anexcess of oxygen. have had good results'with cobalt, platinum chromium and iridium by the sole use o hydrogen.

.Using my process, I have successfully lated silver and other metals` in var ing thicknesses upon negative and positive lms and-prints, including motion-picture films and steropticon slides; also directly upon non-metallic objects, such as plant-leaves, insects, iiowers, corals, shells, cameos an earls. The electro-depositionof metals and alloys on the latter mentioned articles is. of-

h value for the following reason:

A piece of jewelry set with coral, cameos', pearls, shell, 0r other organic substances can not be plated in a solution which attacks these such as chromic acid solutions. A piece of jewelry plated with chromium cannot be lset after plating, as the plate is too hard or brittle. However, by irst plating such organic substances with a metal upon which chromiumcannot be plated in an ordinary solution, such organic subtsances can then be set intov pieces of jewelry and the piece A can be chromium plated man ordinary solution, and then the plate on the inset part re moved with an 'acid that will dissolve its `lated coating without attacking either the chromium plate or the set part. r

The results obtainedfmy present process Y I ascribe to: (a) The i terruption by means of an active gas of the fio of the electric current within a plating solution. This interruption may be complete or incomplete, passf or intermittently. (b) The chemical action, the .electrolytic action and the solution, the either of these.

I desire it to be understood that the expression gas under pressure in this specification and in the following Vclaims means a gasnot anode and the cathode or l ro'duced within the solution or electrolyte, ut brought 4tothe solutionor electrolyte from Without by means of a conduit or similar gas conveying medium.

In general, the gas pressure should be suficient to allow the gas to How, While the volume should be great enough to almost completely envelope the submerged sections of the anodes. Platinum, tungsten, lead, steel or carbon a-nodes may be used With about equally good results. In the plating of cadmium, nickel, zinc, copper, silver, palladium and gold, soluble ano-des of the corresponding metals maj.T be used in the manner above eX- plained. nodes should be Well distributed along the walls of the tank, their combined submerged area being about one-half of that usually required for the particular metal in question. In plating with the described formulas, I have successfully used an area about one-(uarter that of the cathode surface.

I c aim as new, and desire to secure by Letters Patent: 1. The method of electro-deposition of metals and alloys, which consists in conveying hydrogen gas and emitting the gas, under pressure, in contact' with an electrolyte While an electric current is passed through the electrolyte. 3o 2. The method of Velectro-deposition of metals and alloys, which consists in conveying and emitting hydrogen gas, under regulated pressure, below the surface of an electrolyte while an electric current is passed throu l1 the electrolyte.

3. he method of electro-deposition of metals and alloys, which consists in emittingY hydrogen gas, under regulated pressure, from an insoluble tubular ano-de in contact with an 40 electrolyte, while an electric current is passed from said anode through the electrolyte.

4f. The method of electro-deposition of metals and alloys, which consists in surrounding an anode with hydrogen gas under regulated pressure, while partly submerged in an electrolyte.

5, The method of electro-deposition of metals and alloys, which consists in surrounding an anode with hydrogen under pressure,

while artly submerged in an electrolyte.

6. he method of electro-deposition of metals and alloys which consists in conveying and emitting as under a regulatable pressure immediately low the sur ace of an electrol -e while an electric current isu passed t rough the electrolyte.

LESLIE LLOYD LINICK. 

